/*
 * @(#)Rot13Encoder.java	1.0 Mar 7, 2008
 *
 *	The MIT License
 *
 *	Copyright (c) 2008 Malachi de AElfweald <malachid@gmail.com>
 *
 *	Permission is hereby granted, free of charge, to any person obtaining a copy
 *	of this software and associated documentation files (the "Software"), to deal
 *	in the Software without restriction, including without limitation the rights
 *	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *	copies of the Software, and to permit persons to whom the Software is
 *	furnished to do so, subject to the following conditions:
 *
 *	The above copyright notice and this permission notice shall be included in
 *	all copies or substantial portions of the Software.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *	THE SOFTWARE.
 */
package org.eoti.io.encoding;

public class Rot13Encoder
{
	public static final String encode(String toEncode){return rot(toEncode);}
	public static final String decode(String encoded){return rot(encoded);}

	private static final String rot(String source)
	{
		StringBuilder sb = new StringBuilder();
		char c;
		for(int i=0; i<source.length(); i++)
		{
			c = source.charAt(i);
			if(c >= 'A' && c <= 'M')
				sb.append((char)((int)c + 13));
			else if(c >= 'N' && c <= 'Z')
				sb.append((char)((int)c - 13));
			else if(c >= 'a' && c <= 'm')
				sb.append((char)((int)c + 13));
			else if(c >= 'n' && c <= 'z')
				sb.append((char)((int)c - 13));
			else
				sb.append(c);
		}

		return sb.toString();
	}

	public static void main(String ... args)
	{
		for(String arg : args)
			System.out.format("'%s' = '%s'\n", arg, rot(arg));
	}
}
